arduino based time and temperature display

USE OF CALLOC

#include<stdio.h>
#include<stdlib.h>
int main()
{
 int num,i,*ptr,sum=0;
 printf("enter number of elements:");
 scanf("%d",&num);
 ptr=(int*)calloc(num,sizeof(int));//only //difference is on the syntax there is comma //in caaloc and                                                                                  //*(star)in malloc
 if(ptr==NULL)
 {
  printf("error !memory not allocated ");
  exit(0);
 }
 printf("enter element of array:");
 for(i=0;i<num;i++)
 {
  scanf("%d",ptr+i);
  sum=sum+(*(ptr+i));
 
 }
 printf("SUM=%d",sum);
 free(ptr);
 return 0;
}

USE OF MALLOC

#include<stdio.h>
#include<stdlib.h>
int main()
{
 int num,i,*ptr,sum=0;
 printf("enter number of elements:");
 scanf("%d",&num);
 ptr=(int*)malloc(num*sizeof(int));
 if(ptr==NULL)
 {
  printf("error !memory not allocated ");
  exit(0);
 }
 printf("enter element of array:");
 for(i=0;i<num;i++)
 {
  scanf("%d",ptr+i);
  sum=sum+(*(ptr+i));
 
 }
 printf("SUM=%d",sum);
 free(ptr);
 return 0;
}

binary search in a array

#include<stdio.h>
int main()
{
int a[10];
int i,k,mid,l=0,u=8,item;
for(i=0;i<10;i++)
{
scanf("%d",&a[i]);
}
mid=(0+9)/2;
printf("enter the number to search: ");
scanf("%d",&item);
while(l<=u)
{
if(item==a[mid])
{

printf("%d", mid+1);
break;
  }
else if(item<a[mid])
u=mid-1;
else
l=mid+1;


}
}

file handling read and write in text

#include<stdio.h>
#include<conio.h>
int main()
{
FILE *f;
char c;
f=fopen("data.txt","w");
while(c!='.') //it will terminate the loop when u enter the full stop(.)
            
{
c=getche();
fputc(c,f);

}
fclose(f);
printf("\ncontent of field are :");
f=fopen("data.txt","r");
while(!feof(f))
{
printf("%c",fgetc(f));
}
}
                            OUTPUT

input and output using structure

#include<stdio.h>
struct student 
{
int reg_no;
int roll_no;
float marks ;

char name[25];



};

main()
{

struct student s1;
printf("\nEnter the student registration number :");
scanf("%d",&s1.reg_no);
printf("\nEnter the rollnumber: ");
scanf("%d",&s1.roll_no);
printf("\nEnter the marks :");
scanf("%f",&s1.marks);
printf("\nEnter the name :");
scanf("%s",&s1.name);
printf("\nParticulars enter by the user :");
printf("\nStudent registration number :%d",s1.reg_no);
printf("\nStudent roll number :%d",s1.roll_no);
printf("\nStudent name :%s",s1.name);
printf("\nStudent marks :%f",s1.marks);
}

program to count vowels and consonats using pointer

#include<stdio.h>
int main()
{
char a[20],t,m,*p;
int i;
printf("enter the string");
gets(a);
p=a;
for(i=0;*(p+i)!='\0';i++)
{
if(*(p+i)=='a'||*(p+i)=='e'||*(p+i)=='i'||*(p+i)=='o'||*(p+i)=='u')
{
t++;
}
 else 
   m++;
}
printf("the total number of vowels :%d",t);
printf("\nthe total number of consonats :%d",m);
}

DELETION OF ELEMENT IN ARRAY USING POINTER

#include<stdio.h>
#include<conio.h>
main()
{
int n,a[100],i,j,d,*P;
printf("enter the size of array\n");
scanf("%d",&n);
printf("enter the elements of array\n");
for(i=0;i<n;i++)
{
scanf("%d",&a[i]);
}
printf("enter the place to delete");
scanf("%d",&d);
printf("elements after deletion\n");
P=&a[d-1];
for(i=d-1;i<n;i++)
{
*P=a[i+1];
P++;
}
for(i=0;i<n-1;i++)
{
printf("%d\n",a[i]);
}
getch();
}

DELETION OF ELEMENT IN ARRAY

#include<stdio.h>
#include<conio.h>
main()
{
int n,a[100],i,j,d;
printf("enter the size of array\n");
scanf("%d",&n);
printf("enter the elements of array\n");
for(i=0;i<n;i++)
{
scanf("%d",&a[i]);
}
printf("enter the place to delete");
scanf("%d",&d);
printf("elements after deletion\n");
for(i=d-1;i<n;i++)
{
a[i]=a[i+1];
}
for(i=0;i<n-1;i++)
{
printf("%d\n",a[i]);
}
getch();
}

INSERTION OF ELEMENT IN ARRAY USING POINTER

#include<stdio.h>
#include<conio.h>
main()
{
int n,a[100],i,j,d,*p,g;
printf("enter the size of array\n");
scanf("%d",&n);
printf("enter the elements of array\n");
for(i=0;i<n;i++)
{
scanf("%d",&a[i]);s
}
printf("enter the place to insert element\n");
scanf("%d",&d);
printf("enter the element to insert");
scanf("%d",&g);
p=&a[n];
for(i=n;i>=d;i--)
{
*p=a[i-1];
p--;
}
a[d-1]=g;
for(i=0;i<=n;i++)
{
printf("%d",a[i]);
}
getch();
}

INSERTION OF ELEMENT IN ARRAY

#include<stdio.h>
#include<conio.h>
main()
{
int n,a[100],i,j,d,g;
printf("enter the size of array\n");
scanf("%d",&n);
printf("enter the elements of array\n");
for(i=0;i<n;i++)
{
scanf("%d",&a[i]);
}
printf("enter the place to insert element\n");
scanf("%d",&d);
printf("enter the element to insert");
scanf("%d",&g);
for(i=n;i>=d;i--)
{
a[i]=a[i-1];
}
printf("elements after insertion\n");
a[d-1]=g;
for(i=0;i<=n;i++)
{
printf("%d\n",a[i]);
}
getch();
}

LENGTH OF STRING USING POINTER

#include<stdio.h>
#include<conio.h>
#include<string.h>
main()
{
char a[100],i,*p,length=0;
printf("enter the string"); 
gets(a);
p=&a[0];

while(*p!='\0')
{
length++;
p++;
}

printf("length of string=%d",length);
getch();
}

sum of array elements using pointer

#include<stdio.h>
#include<conio.h>
main()
{
int n,i,*p,sum=0;
printf("enter the size of the array");
scanf("%d",&n);
int a[n];
        printf("enter the elements of array");
for(i=0;i<n;i++)
{
scanf("%d",&a[i]);
}
p=&a[0];
for(i=0;i<n;i++)
{
sum=sum+*p;
p++;
}
printf("sum of array element=%d",sum);
getch();
}

FIND THE GREATEST NUMBER IN A ARRAY

#include<stdio.h>
int main()
{
int a[10];
int i,j,t,n;
scanf("%d",&n);
for(i=0;i<n;i++)
{
scanf("%d",&a[i]);

}
for(j=n-2;j>=0;j--)
{
for(i=0;i<=j;i++)
{
if(a[i]>a[i+1])
{

t=a[i];
a[i]=a[i+1];
a[i+1]=t;
}
}
}

printf("\n%d",a[n-1]);



}

program to lowercase a string or word without using strlwr() function

#include<stdio.h>
#include<string.h>
int main()
{
char a[10],b[10];
int i,j[10],len;
printf("enter first  the string");
gets(a);
 
for(i=0;a[i]!='\0';i++)
{
if(a[i]>='A'&&a[i]<='Z')
{
a[i]=a[i]+32;
}
}
printf("the lower string is :");
puts(a);
}

program to lowercase a string or word using strlwr() function

#include<stdio.h>
#include<string.h>
int main()
{
char a[10];
int i;
printf ("enter the string :");
gets(a);
strlwr(a);
printf("the lower case string :");
puts(a);
}

program to uppercase a string or word without using strupr() function

#include<stdio.h>
#include<string.h>
int main()
{
char a[10],b[10];
int i,j[10],len;
printf("enter first  the string");
gets(a);
 
for(i=0;a[i]!='\0';i++)
{
if(a[i]>='a'&&a[i]<='z')
{
a[i]=a[i]-32;
}
}
printf("the upper string is :");
puts(a);
}

program to upper case a string

#include<stdio.h>
#include<string.h>
int main()
{
char a[10];
int i;
printf ("enter the string :");
gets(a);
strupr(a);
printf("the upper case string :");
puts(a);
}

to reverse a string or word without using strrev() function

#include<stdio.h>
#include<string.h>
int main()
{
char a[10],b[10];
int i,j,len;
printf("enter first  the string");
gets(a);
len=strlen(a)-1;
for(i=0;a[i]!='\0';i++)
{
b[len]=a[i];
len--;

}
b[len]='\0';
printf ("the reverse string is :");
puts(b);
}

to reverse a string or word using strrev() function

#include<stdio.h>
#include<string.h>
int main()
{
char a[10];
int i,j;
printf("enter the string:");
gets(a);
strrev(a);
printf("the reverse of string :");
puts (a);
}

program to concate a string or word without using strcat() function

#include<stdio.h>
#include<string.h>
int main()
{
char a[10],b[10];
int i,j,len;
printf("enter first  the string");
gets(a);
printf("enter second the string");
gets(b);
len=strlen(a);
for(i=len,j=0;b[j]!='\0';i++,j++)
{
a[i]=b[j];
}
a[i]='\0';
printf("the concate string :");
puts(a);



}

to concate a string or word using strcat() function

#include<stdio.h>
#include<string.h>
int main()
{
char s[20],s1[10];
printf("enter the  first string:");
gets(s);
printf("enter the  second string:");
gets(s1);
strcat(s,s1);
printf(" the concate string is:%s",s);
}

To find lenght of a string or word without using strlen() function

//to find lenght of a string or word without using strlen() function

#include<stdio.h>

int main()
{
char s[20];
int i,count=0;
printf("enter the string:");
gets(s);
for(i=0;i<20;i++)
{
if(s[i]!='\0')
{
      count++;
    }
else if(s[i]=='\0')
{
break;

}
}
printf("\nThe lenght of the string :%d",count);
}

To find lenght of a string or word using strlen() function

//to find lenght of a string or word  using strlen() function

#include<stdio.h>
#include<string.h>
int main()
{
char s[20],s1[10];
printf("enter the string:");
gets(s);
int l=strlen(s);
printf("\nThe lenght of the string is =%d",l);

}

MULTIPLY OF TWO MATRICES IN C

#include<stdio.h>
int main()
{
int a[3][3],b[3][3],c[3][3],i,j,sum=0,k;
printf("enter the matrix");
for(i=0;i<3;i++)
{
       for(j=0;j<3;j++)
  {
  scanf("%d",&a[i][j]);
}
}
for(i=0;i<3;i++)
{
       for(j=0;j<3;j++)
  {
  printf("%d\t",a[i][j]);
        }
printf("\n");
}
printf("enter the matrix B:\n");
for(i=0;i<3;i++)
{ 
       for(j=0;j<3;j++)
  {
  scanf("%d",&b[i][j]);
}
}
printf(" the matrix B:\n");
for(i=0;i<3;i++)
{
       for(j=0;j<3;j++)
  {
  printf("%d\t",b[i][j]);
        }
printf("\n");
}
for (i = 0; i < 3; i++) 
{
      for (j = 0; j < 3; j++) 
 {
        for (k = 0; k < 3; k++) 
{
          sum = sum + a[i][k]*b[k][j];
        }

       c[i][j] = sum;
        sum = 0;
      }
    }
    printf(" the matrix C(multiply of a and b):");
printf("\n");
for(i=0;i<3;i++)
{
       for(j=0;j<3;j++)
  {
  printf("%d\t",c[i][j]);
        }
printf("\n");
}




}



//FOR ANY QUERY SEND YOUR MESSAGE ON MY EMAILID //ajitkumars2221999@gmail.com
//thank you

PROGRAM TO SUM OF DIAGONAL MATRIX IN C

#include<stdio.h>

int main()

{

int a[3][3],b[3][3],c[3][3],i,j,sum=0;

printf("enter the matrix A:");

for(i=0;i<3;i++)

{

       for(j=0;j<3;j++)

  {

  scanf("%d",&a[i][j]);

}

}

printf(" the matrix A:\n");

for(i=0;i<3;i++)

{

       for(j=0;j<3;j++)

  {

  printf("%d\t",a[i][j]);

        }

printf("\n");

}

for(i=0;i<3;i++)

{

       for(j=0;j<3;j++)

  { if(i==j)

    {

  

  sum=sum+a[i][j];

     }

        }

}

printf("the sum of diagonal of the matrix are:%d",sum);

}

PROGRAM TO PRINT DIAGONAL ELEMENTS IN MATRIX IN C

#include<stdio.h>
int main()
{
int a[3][3],b[3][3],c[3][3],i,j,sum;
printf("enter the matrix A:");
for(i=0;i<3;i++)
{
       for(j=0;j<3;j++)
  {
  scanf("%d",&a[i][j]);
}
}
printf(" the matrix A:\n");
for(i=0;i<3;i++)
{
       for(j=0;j<3;j++)
  {
  printf("%d\t",a[i][j]);
        }
printf("\n");
}
printf("the diagonal of the matrix are:");
for(i=0;i<3;i++)
{
       for(j=0;j<3;j++)
  { if(i==j)
    {
  
  printf("%d\t",a[i][j]);
     }
        }

}
}

PROGRAM TO TRANSPOSE MATRIX IN C

#include<stdio.h>
int main()
{
int a[3][3],b[3][3],c[3][3],i,j,sum;
printf("enter the matrix A:");
for(i=0;i<3;i++)
{
       for(j=0;j<3;j++)
  {
  scanf("%d",&a[i][j]);
}
}
printf(" the matrix A:\n");
for(i=0;i<3;i++)
{
       for(j=0;j<3;j++)
  {
  printf("%d\t",a[i][j]);
        }
printf("\n");
}
printf(" Transpose of matrix A:\n");
for(i=0;i<3;i++)
{
       for(j=0;j<3;j++)
  {
  printf("%d\t",a[j][i]);
        }
printf("\n");
}
}

PROGRAM TO ADD COLOUMN ELEMENTS IN MATRIX

#include<stdio.h>

int main()

{

int a[3][3],i,j,sum;

printf("enter the matrix");

for(i=0;i<3;i++)

{

       for(j=0;j<3;j++)

  {

  scanf("%d",&a[i][j]);

}

}

for(i=0;i<3;i++)

{

       for(j=0;j<3;j++)

  {

  printf("%d\t",a[i][j]);

        }

printf("\n");

}

for(i=0;i<3;i++)

{ sum=0;

       for(j=0;j<3;j++)

  {

  sum=sum+a[j][i];

}

printf("the sum of coloumn%d is =%d\n",i+1,sum);

}

}